The ambient acoustic environment of the ocean is highly variable. At a given time and place, a broad range
of sources may be combined. In addition, conditions at a particular location may affect how well ambient
sounds are received (e.g., sound propagation, water depth, bathymetry, and depth). Natural phenomena
known to contribute to oceanic ambient noise include: (a) wind, sea state and swell patterns, (b) bubble
distributions, (c) currents and turbulence, (d) seismic activity, (e) precipitation, (f) ice cover and activity,
and (g) marine life.